package zlx.springcloud.lb;


import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

@Component
public class MyLB implements LoadBalancer {

    private AtomicInteger atomicInteger=new AtomicInteger(0);

    public final int getAndIncrement(){
        int current;
        int next;
        do{
            current=this.atomicInteger.get();
            next=current>=2147483647 ? 0 : current+1;
        }while (this.atomicInteger.compareAndSet(current,next));
        System.out.println("******第几次访问：次数next："+next);
        return next;
    }

    //负载均衡算法：rest接口第几次请求数 % 服务器集群总数量 = 实际调用服务器下标，每次服务器重启后rest计数从1开始
    @Override
    public ServiceInstance instance(List<ServiceInstance> serviceInstances) {
        int index = getAndIncrement() % serviceInstances.size();
        return serviceInstances.get(index);
    }
}
